简介: |
报告摘要：
Collisions between relativistic heavy-ions (gold or lead) are energetic enough to vaporize the participating
neutrons and protons creating an equilibrated plasma of quarks and gluons. This plasma is thought to be similar
to the state of the universe about one microsecond after the big bang. The existence of this deconfined partonic
phase has been well established an the top energies available at the Relativistic Heavy Ion Collider (RHIC) and the
Large Hadron Collider (LHC). However, this plasma is a new and complicated phase of matter; the nature
of the force between objects operating under the color force is quite different from those interacting through
the electromagnetic force, which has driven our understanding of what it means to be 'matter' or to be a 'phase
of matter'. Although we have made progress in understanding the nature of hot dense nuclear matter, there
are still important open questions about how the matter undergoes the transition between a quark-gluon plasma and a hot hadronic gas.
If the plasma has an equal mix of quarks and anti-quarks, lattice QCD calculations now tell us that there will be a crossover transition. However, in heavy-ion collisions, we create systems with an excess of quarks, and under these circumstances we expect a
first order phase transition, the termination will be a critical point. RHIC has performed a scan of several
beam energies in order to map the QCD matter phase diagram. This talk will report on the conclusions
drawn from that program and outline what remains to be done in a follow-up energy scan program
scheduled for 2019 and 2020.
报告人简介：
Daniel Cebra，美国加州大学戴维斯分校教授。从事相对论重离子碰撞的实验研究，
探索极端高温高密条件下的物质形态、核物质状态方程以及QCD相变。先后参与CERN/SPS NA49，
BNL/AGS E895和BNL/RHIC STAR等重离子物理实验研究工作，曾任STAR实验国际合作组
顾问委员会以及技术委员会成员等职务。
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